Financing Receivables - By Portfolio Segment (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($) item	Dec. 31, 2015 USD ($)
Total Lease Receivable and Loan Receivable Portfolio Segments
Financing receivables:
Number of portfolio segments | item	2
Number of classes of financing receivable | item	2
Financing receivables on a gross basis	$ 18,727	$ 19,945
Collectively evaluated for impairment	18,163	19,406
Individually evaluated for impairment	564	539
Allowance for credit losses:
Allowance for credit losses, beginning balance	590	561
Write-offs	(27)	(62)
Provision	76	141
Other	11	(51)
Allowance for credit losses, ending balance	649	590
Collectively evaluated for impairment	119	79
Individually evaluated for impairment	531	511
Total Lease Receivable and Loan Receivable Portfolio Segments | Major Markets
Financing receivables:
Financing receivables on a gross basis	14,433	15,256
Collectively evaluated for impairment	14,334	15,180
Individually evaluated for impairment	99	76
Allowance for credit losses:
Allowance for credit losses, beginning balance	109	111
Write-offs	(3)	(14)
Provision	12	20
Other	3	(8)
Allowance for credit losses, ending balance	121	109
Collectively evaluated for impairment	36	43
Individually evaluated for impairment	85	65
Total Lease Receivable and Loan Receivable Portfolio Segments | Growth Markets
Financing receivables:
Financing receivables on a gross basis	4,294	4,689
Collectively evaluated for impairment	3,829	4,227
Individually evaluated for impairment	465	462
Allowance for credit losses:
Allowance for credit losses, beginning balance	481	450
Write-offs	(25)	(48)
Provision	64	122
Other	8	(43)
Allowance for credit losses, ending balance	528	481
Collectively evaluated for impairment	82	36
Individually evaluated for impairment	446	445
Lease receivables
Financing receivables:
Financing receivables on a gross basis	6,833	7,041
Allowance for credit losses:
Allowance for credit losses, beginning balance	213	165
Allowance for credit losses, ending balance	222	213
Lease receivables | Major Markets
Financing receivables:
Financing receivables on a gross basis	5,355	5,517
Allowance for credit losses:
Allowance for credit losses, beginning balance	25	32
Allowance for credit losses, ending balance	36	25
Lease receivables | Growth Markets
Financing receivables:
Financing receivables on a gross basis	1,478	1,524
Allowance for credit losses:
Allowance for credit losses, beginning balance	188	133
Allowance for credit losses, ending balance	186	188
Loan receivables
Financing receivables:
Financing receivables on a gross basis	11,894	12,904
Allowance for credit losses:
Allowance for credit losses, beginning balance	377	396
Allowance for credit losses, ending balance	428	377
Loan receivables | Major Markets
Financing receivables:
Financing receivables on a gross basis	9,077	9,739
Allowance for credit losses:
Allowance for credit losses, beginning balance	83	79
Allowance for credit losses, ending balance	85	83
Loan receivables | Growth Markets
Financing receivables:
Financing receivables on a gross basis	2,817	3,165
Allowance for credit losses:
Allowance for credit losses, beginning balance	293	317
Allowance for credit losses, ending balance	$ 343	$ 293